8.5/10 for me I think, on the first watch.
Really a film to be enjoyed in the theatre IMO. The visuals and the sound design especially were very impressive and I couldn't imagine a home experience living up unless you have a very nice setup.
I've seen a bit of complaining about the amount of exposition in the first half, but really there is SO much lore and worldbuilding that just can't be done without a bit of exposition and explaining. There is loads left unexplained here, which I think is okay, but they certainly could have overdone it. Imagine if one of them just did "the voice" without some sort of explanation, for example, it wouldn't make any sense. I think the exposition they did do was pretty organic, and fit well within the narrative. The one case I thought was a bit too much was when Paul explained sand gliding to Jessica...felt unnecessary since they had already shown him watching the film.
The mentats and Dr. Yueh IMO did not get enough development or explanation. Especially Yueh who plays such a pivotal role in the story.
I'm a big fan of the books if it wasn't obvious. I hope they greenlight part 2. As a standalone film it feels really unfinished.